Abstract: The daylight stability, foaming characteristics, color, engine performance test behavior, oxygenates content, and thermal stability of wax isomerate oils and/or hydrocarbon synthesis liquid products are improved by the process of contacting the aforesaid wax isomerate oil and/or hydrocarbon synthesis liquid products with a silica adsorbent, said silica adsorbent being characterized by possessing a pore size of at least about 100 .ANG., preferably at least about 125 .ANG., most preferably at least about 150 .ANG., an alkali/alkaline earth ion concentration, excluding sodium, of greater than about 125 ppm, an iron content of less than about 40 ppm and a zirconium content of less than about 130 ppm.
Type:
Grant
Filed:
July 2, 1993
Date of Patent:
November 14, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
Bal K. Kaul, Craig Y. Sabottke, Rocco A. Fiato, Edward Niessen
Abstract: The presence of carryunder in the extract phase recovered from a solvent extraction tower is an indication of unsatisfactory performance. The continuous analysis of the extract phase using a turbidity analyzer to detect the presence of two phases, indicating carryunder permits corrective measures to be taken in tower operation to reduce or eliminate carryunder.
Type:
Grant
Filed:
April 29, 1994
Date of Patent:
November 14, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
Joseph P. Boyle, Gordon C. Camano, Randall S. Lachine, Howard R. Lingley, Raymond W. Saunders
Abstract: By this invention there is provided a catalyst composition comprising a Group IVB oxide, an amorphous silica-alumina support having dispersed thereon a rare earth oxide, which as herein used also includes yttrium oxide, and a metal(s) selected from the group consisting of Group VIII noble metal(s), mixtures of Group VIII noble metal(s) and tin, mixtures of Group VIII noble metal(s) and rhenium, and mixtures of Group VIII noble metal(s), tin and rhenium. The amorphous silica-alumina support contains at least about 50% silica by weight. The catalyst can function as a hydrocarbon conversion catalyst in reactions where platinum on halided (Cl,F)-alumina is typically used.
Type:
Grant
Filed:
December 20, 1994
Date of Patent:
October 10, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
Stuart L. Soled, Gary B. McVicker, William E. Gates, Sabato Miseo
Abstract: The present invention is directed to materials which improve the cetane number of diesel fusel when added in an amount in the range of 0.01 to 2 wt % to such fuel. The materials are the nitration product of alcohols obtained by the reduction of tall oil fatty acids, tall oil fatty acid esters, vegetable oils and mixtures thereof.
Type:
Grant
Filed:
December 2, 1994
Date of Patent:
October 3, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
Marc-Andre Poirier, David E. Steere, James A. Krogh
Abstract: The oxidation stability of lube base oils is improved by the addition of tetralins or combination of tetralins and organic sulfides. The addition of tetralins or combination of tetralins and organic sulfides to formulated lube oils has also been found to improve the oxidation stability of such formulated oil.
Abstract: The solvent extraction of aromatics containing oil using a selective aromatics extraction solvent to produce an aromatics rich extract phase and an oil rich/aromatics lean raffinate is improved by the steps of subjecting the extract phase to a membrane separation step to produce a permeate phase and a retentate phase passing the retentate phase to a settling zone wherein the retentate phase spontaneously separates into two liquid phases, and recycling the upper phase to the extraction zone, either to the feed inlet or to the bottom of the extract reflux zone to thereby increase the raffinate oil recovered from the extraction tower. Alternatively or in addition to the above, a side stream can be taken from an intermediate zone of the extraction zone (e.g. extraction tower) and fed to a membrane separation to produce a solvent rich permeate and an oil rich retentate.
Abstract: A feed stream comprising a mixture of at least two separable components is separated into a permeate rich in one or more components and a retentate lean in those same components by a process comprising dissolving the feed in a supercritical solvent under supercritical conditions to produce a solution and contacting the solution with a dense, non-porous perstraction membrane having a first and a second surface, said contacting being along a first surface, wherein a portion of the feed dissolves into the first surface of the membrane, migrates through the perstraction membrane under a concentration gradient and emerges from the membrane at the second surface, as a permeate, the permeate being removed from the second surface by use of a sweep fluid comprising a supercritical solvent at supercritical conditions which may be the same as or different from the supercritical solvent in which the feed is dissolved.
Abstract: The present invention is directed to novel catalyst compositions, their preparation, and their use in a selective paraffin isomerization process. The solid acid catalyst compositions comprise a silica support, a Group VIII metal, and a heteropolyacid selected from the group consisting of 12-tungstophosphoric acid, 12-tungstosilicic acid, the exchanged aluminum salt of 12-tungstophosphoric acid, the exchanged aluminum salt of 12-tungstosilicic acid and mixtures thereof. The use of said catalysts in an isomerization process comprises contacting said catalysts with a feed comprising C.sub.n or C.sub.n + paraffins, wherein n=4.
Type:
Grant
Filed:
May 6, 1993
Date of Patent:
May 30, 1995
Assignee:
Exxon Research and Engineering Company
Inventors:
Stuart L. Soled, Gary B. McVicker, Sabato Miseo, William E. Gates
Abstract: The pervaporative treatment of hydrocarbon feeds which have been exposed to air or oxygen and which contain mixtures of aromatic and non-aromatic hydrocarbons to selectively separate the feed into an aromatics rich stream and a non-aromatics rich stream is improved by the step of pretreating the hydrocarbon feed over an adsorbent such as attapulgite clay.
Type:
Grant
Filed:
September 21, 1993
Date of Patent:
May 16, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
Charles P. Darnell, Tan J. Chen, Enrique F. Juarez
Abstract: Batch auto-refrigerative dewaxing processes employing at least two batch chilling vessels can be improved by integrating the batch auto-refrigerative dewaxing chilling cycles of the chilling vessels so as to have their cycles of operation overlap and use thermocompressors to recover the energy of the hot, high pressure cycle stream of one vessel by operation on the cooler, low pressure cycle stream of the other vessel to increase the pressure of said low pressure cycle stream. The overlap operation of the multiple batch chillers integrated through the thermocompressor will also permit running the cool, low pressure cycle to a pressure even lower than atmospheric without inleakage of air because of the vacuum effect generated by the hot, higher pressure stream running through the thermocompressor. Autorefrigerative dewaxing employs liquified normally gaseous solvents as the chilling solvents such as C.sub.3 -C.sub.4 alkanes/alkenes e.g. propane, propylene, butane, butylene and mixtures thereof.
Abstract: The incremental solvent dilution chilling of 600N waxy oils in a staged agitated chilling tower using cold solvent injection is improved in terms of feed filter rate with respect to a 600N waxy oil having a final boiling point of >600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal chilling rate/stage profile as compared to an equal temperature drop/stage profile in the chilling tower and with respect to a 600N waxy oil having a final boiling point of 600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal temperature drop/stage profile as compared to an equal chilling rate/stage profile in the chilling tower.
Abstract: Lubricating basestock oil suitable for use as such or as blending oil is obtained by the low severity hydrotreatment of industrial circulating oils of the type employed in low severity lubricating applications, and which have been mildly degraded and are no longer suitable for use for their intended purpose.
Abstract: The operation of a hydrocarbon synthesis reactor and catalyst distributed in the reaction slurry therein are improved by the presence in said reactor of one or more vertical downcomers open at both ends with gas disengaging areas located at their top end. The downcomer which circulates catalyst from the top of the reaction slurry to the bottom of said slurry is fully immersed in the reaction slurry and preferably extends from just above the bottom of the reaction zone of the reaction vessel to just below the top surface of the reaction slurry. The bottom end of said downcomer is shielded from intrusion of rising synthesis gas by the placement of a baffle which blocks rising gas entry but facilitates the exit of catalyst and liquid from the bottom of said downcomer and distributes them radially throughout the adjacent reactor slurry.
Type:
Grant
Filed:
December 18, 1992
Date of Patent:
January 17, 1995
Assignee:
Exxon Research & Engineering Co.
Inventors:
William C. Behrmann, Charles H. Mauldin, Larry E. Pedrick
Abstract: Selenium and other non-volatile inorganic contaminants in refinery waste water are removed from said waste water and disposed of by a process comprising subjecting the contaminated waste water stream to a non-chemical concentration process producing a contaminants concentrate stream and a clean water stream and passing the contaminants concentrate stream to a coker unit wherein it is used as coker elutriant to quench the coke.
Abstract: The injection of secondary air into the exhaust system of an internal combustion engine equipped with an electrically heated catalyst (EHC) upstream of a catalytic converter using a secondary pump is controlled by use of a dedicated heated oxygen sensor located downstream of the electrically heated catalyst in the exhaust stream from said EHC. The sensor measures the oxygen content in the EHC exhaust stream and sends a signal to a controller which turns on a secondary air pump when the signal from the heated sensor exceeds a pre-selected set point on the controller thereby injecting supplementary air into the exhaust stream from the internal combustion engine to the EHC.
Abstract: Slurry bubble columns equipped with downcomers which have high efficiency gas disengagement means fitted on top of the slurry liquid reaction mixture comprising an inverted channel having a gas vent extending out of the apex of the inverted channel and a liquid by-pass pipe extending from the side of the inverted channel at a point below the apex to under the liquid level and emptying into the downcomer. The inverted channel is fitted to the top of said downcomer and the bottom edge of which inverted channel is in contact with the surface of the slurry mixture in the slurry bubble column reaction zone. Improved catalyst distribution and circulation, mass and heat transfer results from catalyst in gas-lean slurry flowing through the liquid by-pass tubes in the inverted channel and flowing into and down the downcomer to the bottom of the bubble column reactor.
Abstract: The isomerization activity of hydroisomerization catalyst is recovered by subjecting the catalyst to a wash using light aromatic solvents at elevated temperature, e.g. toluene at 300.degree. C. This hot aromatic solvent wash may be preceded by a hot hydrogen containing gas strip. Catalyst activity can be maintained by the continuous or periodic addition of light aromatic solvent or light aromatic containing materials to the feeds sent to the isomerization catalyst.
Type:
Grant
Filed:
March 26, 1993
Date of Patent:
April 26, 1994
Assignee:
Exxon Research and Engineering Company
Inventors:
James J. Schorfheide, Biddanda U. Achia
Abstract: Mixtures comprising alcohol/ether/non-linear hydrocarbon are separated using polyester or polyester polyimide copolymer membranes. The mixture is contacted under pervaporation conditions with the membrane and the alcohol selectively permeates through the membrane. In this way alcohol especially C.sub.1 -C.sub.10, preferably C.sub.1 -C.sub.4 alcohols can be effectively removed from the synthesis solutions used for the production of high value ethers such as methyl-tertiary butyl ether (MTBE) or tertiary-amyl methyl ether (TAME) used as octane enhancers in motor fuels.
Type:
Grant
Filed:
November 2, 1992
Date of Patent:
March 15, 1994
Assignee:
Exxon Research and Engineering Company
Inventors:
Joseph L. Feimer, Charles P. Darnell, W. S. Winston Ho
Abstract: The present invention is directed to a polyester/amide membrane, its preparation and its use for organic liquid separation. The polyester/amide membrane is made by reacting a dianhydride with a polyester diol in a 2:1 to 1.05:1 mole ratio to end cap the diol to produce a prepolymer which is reacted with excess thionyl chloride to convert all of the unreacted anhydride and all carboxylic acid groups to acid chloride groups. The resulting acid chloride derivative is dissolved in organic solvent and interfacially reacted with a diamine dissolved in an aqueous solvent. The excess solutions are removed and the resulting thin film membrane is dried. The membranes are useful for organic liquid separations, especially the separation of aromatic hydrocarbons from mixtures of same with non-aromatic hydrocarbons, preferably under perstraction or pervaporation conditions.
Abstract: A novel, high porosity, high surface area catalyst is disclosed which is useful in wax isomerization processes, especially for the production of high viscosity index, low pour point lubricating oil base stocks or blending stocks. The catalyst contains a catalytically active metal component selected from the group consisting of Group VIB and Group VIII metals, and mixtures thereof, preferably Group VIII metals, and mixtures thereof, more preferably noble Group VIII metals and mixtures thereof, most preferably platinum which catalytically active metal component is present in the range of about 0.01 to 5.0 wt %, and a fluorine content in the range of about 0.01 to about 10.0. The catalyst employs a refractory metal oxide support material, one preferably predominantly (i.e., at least 50 wt %) alumina, most preferably completely alumina, e.g., gamma or eta alumina. The finished catalyst has a porosity, expressed in terms of pore volume, of at least about 0.
Type:
Grant
Filed:
August 20, 1992
Date of Patent:
March 1, 1994
Assignee:
Exxon Research and Engineering Company
Inventors:
Ian A. Cody, David H. Dumfries, Arthur H. Neal, Kenneth L. Riley